NASA's Curiosity Mars rover has completed a reconnaissance "walkabout" of the first outcrop it reached at the base of the mission's destination mountain and has begun a second pass examining selected rocks in the outcrop in more detail.

An unmanned Chinese orbiter known as the “Little Flyer” returned to Earth this past weekend after successfully circumnavigating the Moon, becoming the first spacecraft in nearly four decades to make the journey to the planet’s natural satellite and back.

On Friday, China launched its first mission intended to travel to the Moon and return intact. While the current mission is unmanned, it does set the stage for the Asian country to put a man on the Moon in the near future.

For NASA, manned missions to Mars and other deep-space destinations remain an essential goal. However, a new study reveals that researchers are only beginning to understand and characterize the radiation hazards such missions would encounter.

Cassini-Huygens Mission -- The Cassini unmanned space probe is intended to study Saturn and its moons. It was launched on October 15, 1997 and is estimated to enter Saturn's orbit on July 1, 2004. The mission is a joined NASA/ESA project.
Cassini's principal objectives are to:
-- determine the three-dimensional structure and dynamical behavior of the rings
-- determine the composition of the satellite surfaces and the geological history of each object
-- determine the nature and...

A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.